Chip-scale, high-energy optical pulse generation is becoming increasingly important as integrated optics expands into space and medical applications where miniaturization is needed. Q-switching of the laser cavity was historically the first technique to generate high-energy pulses, and typically such systems are in the realm of large bench-top solid-state lasers and fibre lasers, especially in the long wavelength range >1.8 µm, thanks to their large energy storage capacity. However, in integrated photonics, the very property of tight mode confinement that enables a small form factor becomes an impediment to high-energy applications owing to small optical mode cross-sections. Here we demonstrate a high-energy silicon photonics-based passively Q-switched laser with a compact footprint using a rare-earth gain-based large-mode-area waveguide. We demonstrate high on-chip output pulse energies of >150 nJ and 250 ns pulse duration in a single transverse fundamental mode in the retina-safe spectral region (1.9 µm), with a slope efficiency of ~40% in a footprint of ~9 mm². The high-energy pulse generation demonstrated in this work is comparable to or in many cases exceeds that of Q-switched fibre lasers. This bodes well for field applications in medicine and space.

随着集成光学扩展到需要小型化的空间和医疗应用，芯片级高能光脉冲生成变得越来越重要。激光腔的Q开关历史上是第一种产生高能脉冲的技术，通常此类系统属于大型台式固态激光器和光纤激光器领域，特别是在 >1.8 µm 的长波长范围内，由于其巨大的能量存储能力。然而，在集成光子学中，由于光学模式横截面较小，能够实现小形状因数的紧密模式限制的特性成为高能应用的障碍。在这里，我们展示了一种基于高能硅光子学的被动调Q激光器，它使用基于稀土增益的大模式面积波导，具有紧凑的占地面积。我们在视网膜安全光谱区 (1.9 µm) 的单横向基模中展示了 >150 nJ 的高片上输出脉冲能量和 250 ns 的脉冲持续时间，在约 9 的封装内，斜率效率约为 40%毫米² .这项工作中演示的高能脉冲生成可与 Q 开关光纤激光器相媲美或在许多情况下超过Q开关光纤激光器。这对于医学和太空领域的现场应用来说是个好兆头。